The first developer time will be whatever you find it to be. Start with standard dilution for 6.5 minutes at 100 degrees. If the slides are too dark increase the time of the first developer. The second should go to completion so it won't matter as long as it's all getting done.

Remember that these slides are not going to be optimal without the proper developer. They will probably fade and have weird dmax and color shifts.

Rhodes: The normal E6 process includes a chemical that fogs the film for you. Since you don't have it, you'll have to re expose to light. Any light will do. Just use enough and not too much. Simple, right?

Rhodes: The normal E6 process includes a chemical that fogs the film for you. Since you don't have it, you'll have to re expose to light. Any light will do. Just use enough and not too much. Simple, right?

I probably went wrong there aswell. I hung mine up to dry (so I could get it back on the spool for the C-41 step) in full sunlight for about half an hour or so ! If that doesn't qualify as too much then I don't know what does. I reckoned that it was a kind of 'exposure to completion' step if you know what I mean, all the remaining unexposed silver to be exposed for the 2nd dev stage.

Maybe next time I'll reel it out in darkness and maybe give it one pop of a strobe or something. The problem then is waiting for it to dry, I don't think I have anywhere available that's completely dark that would do the trick.

ASA 125 Tungsten sounds like VNF, an old film used for news shows. I don't know whether it was produced in 35mm, but I don't know of any other 125 ASA Ektachrome film. If it is, it requires VNF processing, which is different than E-6, although I don't know how different.

I've an empty carton for a roll of 35mm "High Speed Ektachrome Type B" for tungsten, expiry early 1970's, and 125 ASA. It was labelled for the older E-4 process.

DanielStone: Doesn't matter, as long as it you give it a reasonable amount of exposure, and leave it in the colour developer (C41) long enough.

I've done this kind of thing a lot.

C41 films as reversal in 1+50 Rodinal need 40c and 2 hour 20 min for proper development at box speed, plenty of agitation.

1+25 is with one level teaspoon of salt per 300ml of working solution is 20c, 10min, plenty of agitation.

But 1+25 cannot be used for reversing because it develops colour dyes, you will get 'black' slides, you would then need to fix, bleach, re-expose, Colour Dev (C41 or E6 CD, I use E6 CD and get excellent results), bleach, fix, etc.

Here is the 1+25 method described above, gives a colour neg on either C41 or E6, this is german supermarket ISO200 film, expired.

Also if you use that dilution and time - do not overexpose your C41 film - it will go shitty, you will have plenty of underexposure latitude however.